Temperature effect on seed germination of Lupinus albus, Lupinus angustifolius and Lupinus luteus

In order to evaluate germination response to temperatureof two varieties of Lupinus albus L. (‘Luxor’,‘Rosetta’), L. angustifolius L. (‘Jindalee’, ‘Sonet’) andL. luteus L. (‘Dukat’, ‘Mister’), seeds were subjectedto seven different germination temperatures from5°C to 35°C with step of 5°C. Germination percentageand Mean Germination Time (MGT) were evaluated.Radical elongation was also measured at temperatureof 20°C.L. albus showed an optimal temperatures rangefrom 10 to 30°C with germination next to 100% andwith a MGT decreasing from 10 to 3 days in the sametemperature range. Among varieties, in L. albus, ‘Rosetta’seems to be more tolerant to extreme (low andhigh) temperatures compared to ‘Luxor’. L. angustifoliusand L. luteus showed full germination from 5 to25°C, while at temperatures over 30°C germinationlower than 50% was recorded. MGT ranged between9 and 2 days. In L. angustifolius, ‘Jindalee’ was lesstolerant of ‘Sonet’ to highest temperatures and inL. luteus, ‘Dukat’ showed better germination responseto high temperatures compared to ‘Mister’. Root elongationvaried in relation to varieties.